The present invention relates to a fuel injection control apparatus and a control method in an internal combustion engine. The control apparatus is provided with a fuel injection portion and a control portion. The fuel injection portion injects a fuel which is burned in a cylinder of the internal combustion engine. The control portion controls injection start timing for injecting fuel from the fuel injection portion.
Japanese Laid-Open Patent Publication Nos. 7-174773 and 2002-303199 each discloses a crank angle sensor detecting a crank angle of an internal combustion engine. A toothed rotor made of a magnetic material, that is, a signal rotor is attached to a crankshaft. The crank angle-sensor includes a magnet pickup coil.
The signal rotor has a plurality of teeth provided in an outer periphery at a uniform interval. A part of the outer periphery is provided with no teeth. A reference position of the crank angle is detected by utilizing such the no-tooth portion of the signal rotor.
The shape of the no-tooth portion is different from the shape of the tooth portion. Accordingly, a rising portion of a rectangular wave obtained by shaping the waveform of an output signal at a time of detecting the no-tooth portion is delayed from a rising portion of a rectangular wave obtained by shaping the waveform of an output signal at a time of detecting a normal tooth portion. The control disclosed in Japanese Laid-Open Patent Publication No. 7-174773 accurately determines an instantaneous rotational speed by correcting the delay (deviation) mentioned above.
In order to increase an engine output and an exhaust performance, it is necessary to inject fuel at a proper timing. However, neither of the above publications discloses an idea for injecting the fuel at a proper timing while taking the deviation accompanying the detection of the no-tooth portion.